In the rich text editor:
@Skullizzard
In a comment:
[Skullizzard](https://chowlings.com/user/Skullizzard)
For Names and Avatars:
In the rich text editor:
%Skullizzard
In a comment:
[](https://chowlings.com/user/Skullizzard) [Skullizzard](https://chowlings.com/user/Skullizzard)